Histological Outcomes And Jak-Stat Signalling In Ulcerative Colitis Patients Treated With Tofacitinib

BACKGROUND AND AIMS

Histological outcomes and JAK-STAT signaling were assessed in a prospective ulcerative colitis (UC) patient cohort after 8 weeks treatment with tofacitinib, an oral Janus kinase (JAK) inhibitor.

METHODS

Forty UC patients received tofacitinib 10 mg twice daily for 8 weeks. Treatment response was defined as histo-endoscopic mucosal improvement (HEMI). Histological remission was defined as a Robarts Histopathology Index (RHI) ≤3 points and histological response as 50% decrease in RHI. Mucosal expression of JAK1-3, Tyrosine kinase 2 (TYK2) and total signal transducer and activator of transcription (STAT) 1-6 were assessed using immunohistochemistry (IHC).

RESULTS

At baseline, the median RHI was 14 (interquartile range (IQR) 10-19). Twenty-six of 40 (65%) patients had severe endoscopic disease (endoscopic Mayo score 3) and 31/40 (78%) failed prior anti-TNF treatment. At week 8, 15 patients (38%) had HEMI, 23 patients (58%) histological remission and 34 (85%) histological response. RHI decreased by a median of 14 points (IQR 9-21) in responders (p<0.001) and by 6 points (IQR 0-13) in non-responders (p=0.002). STAT1, STAT3 and STAT5 expression levels decreased significantly in the whole cohort. Responders had lower week 8 STAT1 expression levels compared to non-responders (0.2%, IQR 0.1-2.8 vs 4.3%, IQR 1.2-11.9, p=0.001), suggesting more profound STAT1 blockade. A trend of higher baseline JAK2 expression was observed in tofacitinib non-responders (2.7%, IQR 0.1-7.7) compared to responders (0.4%, IQR 0.1-2.1).

CONCLUSIONS

Tofacitinib treatment resulted in histological improvement in the majority of UC patients and a substantial decrease of STAT1, STAT3 and STAT5 expression. HEMI was associated with more profound suppression of STAT1.

Assessment of endoscopic response using pan-enteric capsule endoscopy in Crohn's disease; the Sensitivity to Change (STOC) study

BACKGROUND

The potential use of pan-enteric capsule endoscopy (pan-CE) to evaluate mucosal changes during treatment has not been evaluated. We aimed to assess the ability of pan-CE to measure changes in mucosal disease activity before and after starting biologic treatment in Crohn's disease patients.

METHODS

In this two-center prospective study, patients with clinical and biochemical signs of active Crohn's disease underwent pan-CE before and 8 to 12 weeks after treatment initiation with infliximab, adalimumab or vedolizumab. Endoscopic disease activity was assessed using the simple endoscopic score for Crohn's disease (SES-CD) and the Crohn's disease endoscopic index of severity (CDEIS), expanded with two segments (i.e., the jejunum and pre-terminal ileum). Occurrence of endoscopic remission (i.e., absence of ulcers) and endoscopic response (i.e., 50% decrease in SES-CD and CDEIS scores compared to baseline) was assessed and the standardized effect size was calculated.

RESULTS

Twenty-two patients (50% females) completed the study. Endoscopic remission was observed in 6 out of 22 (27%) patients and 13/22 patients (59%) showed an endoscopic response for both the SES-CD and CDEIS score. Median SES-CD and CDEIS scores decreased from 16.0 (IQR 10.0 - 24.0) to 6.0 (IQR 2.8 - 12.0, p = .001) and from 7.1 (IQR 4.6 - 11.2) to 3.0 (IQR 0.9 - 6.0, p = .001), respectively. The standardized effect size was 1.44 and 1.24 for the SES-CD and CDEIS, respectively. No adverse events related to pan-CE were reported.

CONCLUSION

Pan-CE was a useful technique to assess changes in mucosal disease activity in Crohn's disease patients.